Merge pull request #46 from md5/connection-upgrade

Send "Connection: upgrade" when "Upgrade" header is received

nginx.tmpl

@@ -1,8 +1,17 @@
+# If we receive X-Forwarded-Proto, pass it through; otherwise, pass along the
+# scheme used to connect to this server
 map $http_x_forwarded_proto $proxy_x_forwarded_proto {
   default $http_x_forwarded_proto;
   ''      $scheme;
 }
 
+# If we receive Upgrade, set Connection to "upgrade"; otherwise, delete any
+# Connection header that may have been passed to this server
+map $http_upgrade $proxy_connection {
+  default upgrade;
+  ''      '';
+}
+
 server {
 	listen 80 default_server;
 	server_name _; # This is just an invalid value which will never trigger on a real hostname.
@@ -62,7 +71,8 @@ server {
 
 		# HTTP 1.1 support
 		proxy_http_version 1.1;
-		proxy_set_header Connection "";
+		proxy_set_header Upgrade $http_upgrade;
+		proxy_set_header Connection $proxy_connection;
 	}
 }
 {{ end }}